US3742409A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic position indicator
Assignee: Westinghouse Electric Corp
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Filing: 1970-11-27
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Granted: 1973-06-26
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Expires: 1990-11-27
Abstract
Abstract A new type of position indicator is disclosed herein for detecting the presence or absence of magnetic material which operates on the principle of either saturating or not saturating a transformer. The indicator comprises a modified E core having two magnetic flux paths with a portion thereof common to both flux paths. An AC excitation winding is wound in transformer relationship with a secondary detection winding and generates the flux in one of the magnetic paths. The flux in the second magnetic path is generated by a DC excitation winding, which provides a means of saturation control over the E transformer. The DC magnetic circuit is opened or closed by the absence or presence of the magnetic material being detected; the detection winding in the AC circuit being responsive to the corresponding change in flux.
Inventors
- 👤 D Santis
- 👤 A Wavre
- 👤 A Szabo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 20:39
CPC Classifications
G; G21; G21C; G21C17/00; G21C17/10; G21C17/12; Y; Y02; Y02E; Y02E30/00; Y02E30/10; Y02E30/30
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
186 words
A magnetic position indication system for detecting the presence or absence of a movable magnetic member having at least one magnetic position indicator comprising a magnetic core, said magnetic core having a first and a second magnetic loop and a magnetic flux path common to at least a portion of said first and second magnetic loops, the first of said magnetic loops forming a closed magnetic flux path and having AC flux excitation means coupled thereto, the second of said magnetic loops forming a normally opened circuited magnetic flux path and having DC flux excitation means coupled thereto, a movable magnetic member being movable to close the circuit of said second magnetic loop, whereby the presence of said movable member substantially between the open circuit of said second magnetic loop closes the DC magnetic flux path associated therewith to enable the DC flux flowing therein to saturate the magnetic core and thereby increase the reluctance of said common path, detection means in said first magnetic loop responsive to a change in the AC flux flowing therein due to the increased reluctance of said common magnetic path.
Claim 2
Dependent Claim
186 words
A magnetic position indication system for detecting the presence or absence of a movable magnetic member having at least one magnetic position indicator comprising a magnetic core, said magnetic core having a first and a second magnetic loop and a magnetic flux path common to at least a portion of said first and second magnetic loops, the first of said magnetic loops forming a closed magnetic flux path and having AC flux excitation means coupled thereto, the second of said magnetic loops forming a normally opened circuited magnetic flux path and having DC flux excitation means coupled thereto, a movable magnetic member being movable to close the circuit of said second magnetic loop, whereby the presence of said movable member substantially between the open circuit of said second magnetic loop closes the DC magnetic flux path associated therewith to enable the DC flux flowing therein to saturate the magnetic core and thereby increase the reluctance of said common path, detection means in said first magnetic loop responsive to a change in the AC flux flowing therein due to the increased reluctance of said common magnetic path.
Claim 3
Dependent Claim
22 words
The magnetic position indicator of claim 1 wherein said detection means is placed in transformer relationship with said AC flux excitation means.
Claim 4
Dependent Claim
24 words
The magnetic position indicator of claim 1 wherein said AC flux excitation means comprises an AC coil magnetically coupled to said first magnetic loop.
Claim 5
Dependent Claim
45 words
The magnetic position indicator of claim 1 wherein said magnetic core comprises a generally C-shaped core having two open legs and a bight connected therebetween, said open legs being mounted on said housing and at least a portion of said bight being generally theta shaped.
Claim 6
Dependent Claim
23 words
The magnetic position indicator of claim 1 including at least one permanent magnet coupled to at least one loop of said magnetic core.
Claim 7
Dependent Claim
55 words
The magnetic position indication system of claim 1 including a plurality of said magnetic position indicators, and at least a portion of said magnetic position indicators having a common DC flux excitation means comprising at least one winding at least partially enclosing the magnetic cores of each position indicator of said portion of position indicators.
Claim 8
Dependent Claim
52 words
The magnetic position indicator of claim 1 wherein said movable member is so constructed that in at least one of its positions relatively non-magnetic material substantially bridges the open circuit of said second magnetic loop and in its remaining positions magnetic material substantially bridges the open circuit of said second magnetic loop.
Claim 9
Dependent Claim
21 words
The magnetic position indicator of claim 1 wherein said movable member comprises a portion of nuclear reactor control rod drive shaft.
Claim 10
Dependent Claim
31 words
The magnetic position indication system of claim 8 wherein said magneTic position indicator is mounted on a nuclear reactor control rod housing having said control rod drive shaft slidably mounted therein.
Claim 11
Dependent Claim
33 words
The magnetic position indication system of claim 9 including two magnetic position indicators longitudinally spaced along said housing for determining the presence or absence of said control rod shaft at said indicator location.
Claim 12
Dependent Claim
53 words
The magnetic position indication system of claim 10 wherein said control rod shaft is longitudinally movable to an upper and a lower rest position and said magnetic position indicators are substantially located at the upper extremity of said upper rest position and slightly above the upper extremity of said lower rest position respectively.
Claim 13
Dependent Claim
46 words
The magnetic position indication system of claim 9 wherein a plurality of said control rod shafts are circumferentially positioned around the inner wall of said housing and a plurality of said magnetic position indicators are circumferentially positioned around said housing adjacent said control rod shafts respectively.
Claim 14
Dependent Claim
68 words
The magnetic position indication system of claim 12 wherein each of said control rod shafts has a first and a second indicator respectively, said control rod shafts being longitudinally movable to an upper and a lower rest position and said first and second indicators are substantially positioned at the upper extremity of said upper rest position and slightly above the upper extremity of said lower rest position respectively.
Claim 15
Dependent Claim
41 words
The magnetic position indication system of claim 13 wherein said second indicators have a common DC flux excitation means coupled thereto, said DC excitation means comprising at least one winding partially enclosing the magnetic cores of each of said second indicators.
Claim 16
Dependent Claim
46 words
The magnetic position indication system of claim 9 wherein said magnetic core comprises a generally C-shaped core having two open legs and a bight connected therebetween, said open legs being mounted on said housing and at least a portion of said bight being generally theta shaped.
Claim 17
Dependent Claim
78 words
A magnetic position indication system for detecting the presence or absence of magnetic material having a plurality of magnetic position indication means, at least a portion of said magnetic position indication means having a DC flux path and a DC flux excitation means associated therewith, said DC flux excitation means being common to at least two of said indication means, comprising at least one winding at least partially enclosing the DC flux paths of said two indication means.
Claim 18
Dependent Claim
78 words
A magnetic position indication system for detecting the presence or absence of magnetic material having a plurality of magnetic position indication means, at least a portion of said magnetic position indication means having a DC flux path and a DC flux excitation means associated therewith, said DC flux excitation means being common to at least two of said indication means, comprising at least one winding at least partially enclosing the DC flux paths of said two indication means.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-06-25 | 1976-12-25 | 1977-06-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-06-25 | 1980-12-25 | 1981-06-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-06-25 | 1984-12-25 | 1985-06-26 | $7700.00 | Window Closed / Lapsed |